In many laboratory settings, it is often necessary to analyze a large number of chemical or biochemical samples at one time. In order to stream-line such processes, the manipulation of samples has been mechanized. Such mechanized sampling is commonly referred to as autosampling and is performed using an automated sampling device or autosampler.
While a vast array of autosamplers are currently known and available, the majority of such devices share one common feature, employing robotic-like systems to analyze multiple vessels or containers containing samples in a given time. Many such devices are equipped with a robotic manipulator capable of two types of linear movement, i.e., x-y and vertical which allows the manipulator to access a container, transfer the container from a parent machine, and return the container to the appropriate position in the sample tray. Another common style of autosampler is one which employs robotic movement to move a sample probe above a sample vessel, or, alternatively, employs a moving table or conveyer to move the sample vessels underneath the sample probe.
Although autosamplers presently known in the art have greatly increased the ease and efficiency of assaying multiple samples at a given time, such samplers are disadvantageous in that they are likely to introduce an additional source for sample contamination, allowing for contamination of sample vessels by contaminants which may fall into containers during analysis. Present autosamplers employing mechanical parts may cause dust, or the like, to fall into these containers because of mechanical wear of the devices that either is directly above the containers while they are moving or as the containers themselves move underneath a dispensing pipette. Further, such autosamplers are typically not enclosed exposing the samples to particulates and other matter present in the air. In addition, prior art autosamplers often result in sample loss or sample cross-contamination during assaying due to the sample probe of the autosampler moving rapidly and vibrations associated with such rapid movement. Also, it is often desirable to dilute, spike or add a standard addition to a sample prior to analysis. These procedures generally require an additional machine or analyst to measure an amount of diluent, spike or standard addition and add it to the sample.
What is desired, therefore, is an automated sampling device without any mechanical moving parts positioned above stationary samples thereby removing such possible source of contamination. Further, it is desired that the automated sampling device be protected from the external environment by placing the device in an automated sampling device enclosure. A mechanism which allows an autosampler to move rapidly from sample to sample without affecting sample volume or causing sample cross-contamination is also desired. Also, the ability to dilute, spike or otherwise add a fluid to the sample while on the automated sampling device without requiring extra manpower or machinery is desired.